Abstract: A receiver is provided for use in a fiber optic data communication system of the type employing unipolar trapezoidal Manchester data encoding. The receiver of the invention is capable of processing unipolar optical Manchester signals transmitted over optical fibers. The receiver converts the optical signals into electrical base-band signals, and then amplifies, filters and detects the electrical signals to provide standard digital levels at the receiver output. The receiver incorporates direct-current coupled amplifiers, fast automatic gain control circuitry for the amplifiers, direct current offset correction circuitry to prevent drift of the signal base line, and threshold circuitry controlled to assure half peak amplitude, or mid-amplitude, processing of the electrical signals.

Abstract: In order to more efficiently transmit optical data on an optical data bus to a number of members of an optical data transmission community, an electronic active star element which receives signals from each of a plurality of remote terminals, converts the optical signals to electrical signals, amplifies them, and transmits them to the remaining remote terminals is provided.